This invention relates to a communication system for information communication between computers, a server device, a client device, a portable telephone set, a communication method, a concerted processing providing method, a concerted processing method, a billing surrogating method, a content validating method, a program and a recording medium. More particularly, it relates to a communication system for performing concerted processing among plural devices, interconnected over a network, a server device, a client device, a portable telephone set, a communication method, a concerted processing providing method, a concerted processing method, a billing surrogating method, a content validating method, a program and a recording medium.
In keeping pace with the development of information processing apparatus, including computers, first of all, it has become possible to handle digital content, such as music or pictures, referred to below as content, by information processing apparatus, including computers. Moreover, in keeping pace with the development of information communication technology, services which permit variable content to be purchased over a communication network, using information processing apparatus, such as computers, are being offered in increasing numbers.
For example, if a user finds content he/she desires at a shop on the network (server device), he/she is able to download the encrypted content to a client device. At this time point, the content is still in an encrypted state, such that the content is not adequately reproducible, that is, the content is not validated.
The user transmits information necessary for payment of the cost to purchase the content to the server device. The server device then returns information for validating the content, for example, decoding key data, to the client device. Using the information thus sent from the server device, the client device is able to validate the content.
When validated, the content becomes usable in the client device. For example, if the content is music data, the music can be reproduced.
Meanwhile, in a system providing these services, content validation and payment of the cost to purchase must necessarily occur in synchronization with each other. That is, if the process of validating the content is performed, the process of payment of the cost to purchase must necessarily be performed. In a similar manner, when the process of payment of the cost to purchase is performed, the process of validating the content must necessarily be performed.
In data communication over a wide network, such as the Internet, there are occasions where transactions cannot be terminated due to, e.g., network malfunctions. For example, if malfunctions occur on the network as the ID (identification) and the password are being transmitted from the server device to the client device, there arises a situation in which, even though the user has made payment, the user cannot validate the content. If the user information necessary for payment is re-transmitted from the client to the server, the cost is collected in duplicate.
Thus, there is a need for a system which guarantees that, if a network malfunction has occurred, but one of the process of validating the content and the process of payment of the cost to purchase is completed, the other processing can necessarily be completed.